John Horgan stood in front of a modest $1.2 million Burnaby home last week and told struggling families that he will help them to be able to afford housing in B.C., with an ambitious plan critics are calling 'unrealistic.'

"Our plan calls for 114,000 new units to be built over the next 10 years. Co-op housing, rent purpose housing, not-for- profit housing and market based housing," said Horgan.

A pregnant woman holding a baby told him that being able to afford a home with a backyard "would be a game changer" for her family."

"Help is on the way," he replied.

But that help requires a lot of external factors to go Horgan's way should the NDP form government. And few, if any, of the promised homes will be single family dwellings with yards.

"The whole continuum of housing has been neglected by the B.C. Liberals," said Horgan, when he announced what would be the biggest housing program in BC history.

"The cost of that is staggering. It's billions of dollars over the number of years. Where's that money going to come from?" asked Anne McMullen, the president of the Urban Development Institute, which represents developers.

"It might sound good, but when you scratch below the surface I don't know how realistic it is," said McMullen, pointing out that 14 thousand homes are already being built every year in the Lower Mainland.

"Is the government going to take all that over?" McMullen wonders.

NDP plan depends on other governments

The CBC fact check team consulted several housing experts who identified three hurdles in Horgan's plan:

- The federal government would have to pay one third.

- Municipalities would have to donate hundreds of building sites.

- The rezoning process would have to be fast-tracked

The NDP platform includes building 7,000 rental homes a year for 10 years, plus "housing for students, singles, seniors and families, ranging from supported social housing to quality, market rental housing."

"Why the government should be in the business of building market housing is beyond me," said Tsur Somerville, the director of UBC's Centre for Urban Economics and Real Estate.

Somerville questions the need for so many homes, when there are only 15,000 people on B.C. Housing's wait list.

"I think that's a really, really hard case to make," he said.

"That's a phenomenal amount of money for a really large number of units. You're talking about the over-doubling of the existing stock of affordable housing," said Somerville.

Cost of NDP housing promise

The NDP platform does not say what its housing plan will cost.

​"Billions to build, hundreds of millions to operate and maybe billions of dollars in city land, plus a construction industry that is already running at full tilt," said Jordan Bateman, former Canadian Taxpayers Federation spokesperson, and now communications directors with the Independent Contractors and Businesses Association of B.C.

"It is an incredibly unrealistic plan," said Bateman.

Somerville estimates it will cost at least $15 billion, if they can find Crown land and $30 billion if land must be purchased.

​"Even at $200,000 each, that's $22 billion worth of construction, none of which is costed in the platform," said Bateman.

Last year, the B.C. government said its plans to build 2,000 affordable homes over five years would cost $355 million or $177,500 per unit.

$27 billion based on recent example

CBC's fact check team looked at a recent example to get a more realistic figure on the cost of social housing.

The cost per unit to build a 108-unit building at the corner of Abbott and Pender Street in Vancouver is $238,000 and most of the homes were just 324 square feet.

The land was donated by the City of Vancouver to the Atira Women's Resource Society.

At that price, Horgan's plan would cost $27 billion.

CBC requested the NDP's costing of the platform.

"The Rental Housing Coalition estimates a provincial contribution of $400 million a year to build supply," said a statement from the party.

The NDP says it based its housing plan on a report issued by the coalition last month.

Where will land come from?

The province has little Crown land in urban centres, according to a 2010 government report.

"We're going have to work very closely and very aggressively with municipalities," said Kishone Tony Roy, CEO of the B.C Non Profit Housing Association and former constituency assistant to Christy Clark.

Roy is pleased the NDP is taking the advice of housing advocates and he expects cities and the federal government will partner with the province and the non-profit groups that he represents.

"We can come up with a third of it, as well our own members own a lot of land. They have buildings that can be densified and we can raise money," said Roy.

"The NDP plan is a very credible long- term plan to solve the affordable housing crisis ... solve homelessness," said Roy.

He says it's a new model for building homes, where the province and Ottawa pay up front capital costs and non-profits carry mortgages and cover most of the operating costs.

If you have an issue you'd like us to fact check during this election campaign, email at us investigate@cbc.ca. or use the form on our webage to send us your confidential tips.